1997 Ford Explorer P0171 & P0174 Help!!!

[nikko528]

I am in a quandry with my 1997 Ford Explorer (4.0/4WD). The Check Engine Light came on and Auto Zone pulled the codes P0171 and P0174. My husband and I have bought the Haynes Repair Manual and searched various sites for answers. We have verified no leaks, PCV is fine, MAF is fine. We took it to a local Ford Service Center and were told that the Intake Gaskets and the EGR O-Ring was leaking. Point is that the car is not riding rough, minimal noise and none of the 'normal' conditions that you would expect with the lean codes. Any one out there have any other ideas of what to look at?

Thanks in advance!

[shorod]

Welcome to the forum!

The dealer is probably correct about the intake gaskets as those are a common problem on the 4.0L Explorer. Of course, the dealer probably knows this and may have just said that was bad assuming it is the problem.

You may want to review http://www.automotiveforums.com/vbul...ighlight=P0171 and try the carburetor cleaner trick to determine if the intake manifold gasket is leaking.

-Rod

[nikko528]

Okay, checked for leaks with the carborator cleaner and it did not effect the rpm's or make the engine sound any different. We took the car to Emission Inspection because the Ford Dealer would not give us the specific codes that they pinpointed. The OBD Inspection showed P0113 Intake Air Temperature Circuit High Input. So new intake manifold gasket anyway.

Thanks again!

[shorod]

The intake air temperature circuit is not related to the intake manifold gasket set. There is an Intake Air Temperature (IAT) sensor mounted in or near the air filter housing. This is a simple thermistor sensor that helps the PCM determine the air temperature of the air entering the air filter and ultimately the engine intake. Sounds like you might have a faulty IAT sensor or a wiring issue for the IAT sensor. While you're waiting for the gaskets to arrive, check the sensor and wiring for any obvious damage. You may also want to consider cleaning the Mass Air Flow (MAF) sensor with the appropriate cleaner. I'd start with those two items before tearing into the intake manifold to replace the gaskets.

By the way, most of the chain auto parts stores can read and clean diagnostic trouble codes, you won't need to go to the inspection station to clear the IAT code after fixing the IAT sensor or cleaning the MAF. Just be prepared to explain to the parts store what you did to remedy the code. Some of them care, some do not.

-Rod

[nikko528]

We cleaned the MAF during the intial sweep and checked all of the wiring for visable damage. We did not test the connections/output(?) on the MAF. We talked about replacing the MAF originally before this new code came to light. We may try that first then again.

BTW...Auto Zone said that they will not clear codes anymore, something changed that makes it illegal for them to clear the code is what the tech told us. We have not tried any other stores yet.

[jft90]

how do i clean the maf sensor on my 1997 ford explorer

[email protected]

[shorod]

Welcome to the forum!

To clean the MAF sensor you'll need the security torx bit that fits the MAF sensor screws (available and some electronics supply stores and some auto parts stores), a can of Mass Air Flow Sensor (MAFS) Cleaner, and a steady hand. The cleaner that I've seen is made by CRC and is available at least at Advance Auto Parts. I didn't find it at AutoZone when I last looked for it there.

Unplug and unbolt the MAF sensor, remove it from the air intake tube, and clean it per the instructions on the can of cleaner.

-Rod

[jft90]

thank you,

jt